Extreme thermal energy rejection radiator

ABSTRACT

A vehicle is provided which includes an engine and a radiator. The radiator with circulating coolant fluid includes a plurality of embedded heat pipes each having (a) a body with first and second opposing ends, (b) a wicking material, and (c) a thermal transfer fluid, wherein said body of said heat pipe encloses an interior volume, and wherein said wicking material and said working fluid are disposed in said interior volume of said heat pipe. The first end of the heat pipe extracts heat from the engine, and the second end of the heat pipe transfers heat from the heat pipe to an atmosphere external to the engine. The heat transfer fluid transfers heat from the first end of said heat pipe to the second end of said heat pipe, and the wicking material transfers the heat transfer fluid from the second end of the heat pipe to the first end of the heat pipe.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority from U.S. provisional application No. 63/287,424, filed Dec. 8, 2021, having the same inventors and title, which is incorporated herein by referenced in its entirety.

FIELD OF THE DISCLOSURE

The present disclosure pertains generally to thermal management devices, and more particularly to thermal energy rejection radiators which contain a plurality of heat pipes, and which can be used to cool engines.

BACKGROUND OF THE DISCLOSURE

Modern military operations on the battlefield are often conducted in environments of extreme heat, sometimes in excess of 122° F. (50° C.). Typical internal combustion engines are prone to overheating in such environments. Heat rejection, which may be used to cool engines in such environments, is typically a matter of thermodynamics and coefficients of thermal conductivity.

SUMMARY OF THE DISCLOSURE

In one aspect, a vehicle is provided which comprises an engine and a radiator; wherein said radiator includes circulating coolant fluid and a plurality of embedded heat pipes having (a) a body with first and second opposing ends, (b) a wicking material, and (c) a thermal transfer fluid; wherein said body of said heat pipe encloses an interior volume; wherein said wicking material and said working fluid are disposed in said interior volume of said heat pipe; wherein said first end of said heat pipe extracts heat from said engine; wherein said second end of said heat pipe transfers heat from said heat pipe to an atmosphere external to said engine; wherein said heat transfer fluid transfers heat from said first end of said heat pipe to said second end of said heat pipe; and wherein said wicking material transfers said heat transfer fluid from said second end of said heat pipe to said first end of said heat pipe.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a particular, non-limiting embodiment of a heat pipe which may be utilized in radiators of the type disclosed herein.

FIG. 2 is an illustration of a particular, non-limiting embodiment of an extreme thermal energy rejection radiator (ETHERR) of the type disclosed herein.

DETAILED DESCRIPTION OF THE DISCLOSURE

It has now been found that the foregoing problem may be addressed with the radiator system disclosed herein. In a preferred embodiment, the radiator system will have the same volumetric dimensions as the conventional radiator it is replacing. This may be achieved economically by, for example, switching a conventional radiator with an all-aluminum radiator having the same volumetric capacity of cooling fluid, and with the addition of embedded aluminum heat-pipes filled with a suitable thermal transfer fluid (such as, for example, acetone). Heat pipes work without any moving parts or electric energy input. These features make heat pipes very reliable. The basic functions of the heat pipe are based upon evaporative cooling.

In a preferred embodiment of a device in accordance with the teachings herein, one end of the heat pipe is in contact with the heat source and the other is disposed far enough away from the heat source to reject heat from the heat pipe to an external environment. In an especially preferred embodiment, this is achieved through the use of an array of alternating heat pipes, with the hot end embedded within the radiator and the cold end bent around to the back of the radiator. Such a configuration may be, for example, the same as (or similar to) the configuration employed in WO2018045362 (Junio et al.), entitled “Thermoelectric Heat Energy Recovery Module Generator For Application In A Stirling-Electric Hybrid Automobile”, which is incorporated herein by reference in its entirety. The use of acetone as the thermal transfer fluid in the heat pipe is preferred due to its boiling point (50° C.) and compatibility with aluminum, the latter of which has a high coefficient of thermal conductivity, though other suitable fluids (such as, for example, suitable ethers or halogenated ethers) or mixtures of fluids may also be utilized.

FIG. 1 is an illustration of a first particular, nonlimiting embodiment of a heat pipe which may be utilized in the devices and methodologies described herein. As seen therein, the heat pipe 101 comprises a chassis 103 enclosing an interior space 105. The chassis 103 in the particular embodiment depicted is cylindrical in shape but may have various other shapes as well. The chassis 103 preferably comprises a suitable metal, and more preferably comprises aluminum or an aluminum alloy.

A wicking material 107 is disposed on an interior surface of the chassis 103 and contains a heat transfer fluid. The heat pipe 101 includes a first end 109 which is exposed (directly or indirectly) to a heat source at which heat is to be absorbed, and a second end 111 which is exposed (directly or indirectly) to a heat sink (such as, for example, the ambient environment) to which heat can be rejected.

In use, heat is absorbed at a first end 109 of the heat pipe 101, resulting in vaporization of the heat transfer fluid (that is, the heat transfer fluid undergoes a phase transition from a first, liquid phase to a second, gaseous phase). The vaporized heat transfer fluid then flows from the first, heated end 109 of the heat pipe to the second, cooler end 111 of the heat pipe 101, where the vaporized heat transfer fluid undergoes condensation (that is, the heat transfer fluid undergoes a phase transition from the second phase to the first phase) and is reabsorbed into the wicking material 107. The condensed heat transfer fluid is then conducted to the first end 109 of the heat pipe 101 by the wicking material 107 via capillary action.

The heat transfer fluid, which is preferably an organic liquid and more preferably comprises acetone, may be selected to have a desired boiling point. Preferably, the boiling point is no more than 50° C. in the environment inside of the heat pipe.

FIG. 2 is an illustration of a particular, non-limiting embodiment of an extreme thermal energy rejection radiator (ETHERR) 201 of the type disclosed herein. The ETHERR 201 depicted therein may be used in combination with an external combustion engine such as, for example, a Stirling Cycle engine or an Ericsson Cycle engine.

The ETHERR 201 comprises a radiator grating 213 and a series of embedded heat pipes 211. The radiator grating 213 includes a plurality of conduits through which a suitable coolant fluid circulates. The embedded heat pipes 211 wrap around the radiator grating 213 in an alternating fashion. Groups of heat sink fins or pins 212 are disposed in thermal communication with the condensing end of the heat pipes 211. The radiator grating 213 is equipped with an outlet 214 which allows the coolant fluid to exit the radiator grating 213 and circulate through the engine or other thermal energy producing device or heat source. Similarly, the radiator grating 213 is provided with an inlet 215 which allows the coolant to enter the radiator grating 213 from the engine or other thermal energy producing device or heat source. The embedded heat pipes 211 function in the manner described above to absorb heat from the coolant fluid and reject it to the ambient environment.

The above description of the present invention is illustrative and is not intended to be limiting. It will thus be appreciated that various additions, substitutions and modifications may be made to the above described embodiments without departing from the scope of the present invention. Accordingly, the scope of the present invention should be construed in reference to the appended claims. 

What is claimed is:
 1. A vehicle, comprising: an engine; and a radiator; wherein said radiator includes a plurality of embedded heat pipes having (a) a body with first and second opposing ends, (b) a wicking material, and (c) a thermal transfer fluid; wherein said body of said heat pipe encloses an interior volume; wherein said wicking material and said working fluid are disposed in said interior volume of said heat pipe; wherein said first end of said heat pipe extracts heat from said engine; wherein said second end of said heat pipe transfers heat from said heat pipe to an atmosphere external to said engine; wherein said thermal transfer fluid transfers heat from said first end of said heat pipe to said second end of said heat pipe; and wherein said wicking material transfers said heat transfer fluid from said second end of said heat pipe to said first end of said heat pipe.
 2. The vehicle of claim 1, wherein said heat transfer fluid undergoes a phase transition from a first phase to a second phase at said first end of said heat pipe.
 3. The vehicle of claim 2, wherein said heat transfer fluid undergoes a phase transition from said second phase to said first phase at said second end of said heat pipe.
 4. The vehicle of claim 3, wherein said first phase is a liquid phase and said second phase is a gaseous phase.
 5. The vehicle of claim 1, further comprising a heat coil, wherein said second end of said heat pipe transfers heat to an atmosphere external to said engine by way of said heat coil.
 6. The vehicle of claim 5, wherein said heat coil is in thermal communication with a heat vane.
 7. The vehicle of claim 1, wherein said heat transfer fluid comprises an organic liquid.
 8. The vehicle of claim 1, wherein said heat transfer fluid comprises acetone.
 9. The vehicle of claim 1, wherein said heat transfer fluid has a boiling point of no more than 50° C.
 10. The vehicle of claim 1, wherein said engine is an external combustion engine.
 11. The vehicle of claim 10, wherein said engine is selected from the group consisting of Stirling Cycle engines and Ericsson Cycle engines.
 12. The vehicle of claim 1, wherein said body of said heat pipe comprises aluminum. 